The invention concerns the realization of a torque multiplying kinematic device, particularly for bicycles. Many kinematic devices already exist. All of them tend to fulfil the purpose of increasing the torque necessary for the motion of the bicycles while keeping the ensuing muscular effort practically constant.
One of the most immediate solutions consists in the increase of the necessary torque by increasing the length of the bicycle cranks.
Such solution, however valid in principle and possible to realize in the practice, presents some problems. One of the first problems consists in the necessity of lifting the axis of rotation of the cranks in relation to the ground, in order to allow between the pedal, when it is in its lowest dead-end position, and the road surface, a certain safety height, so as to prevent the pedal from scaping on the ground.
A second drawback is represented by the fact that such solution brings about the necessity of increasing the leg-straddling angle necessary for the performance of the thrust of the foot on the pedals.
One more drawback arising from what has just been described consists in that this solution brings about the increase of the angle of inclination of the straight line for the appliance of the thrust on the pedals with the consequent increase of its value, its vertical component usable to generate the motion remaining the same.